There was plenty of praise delivered yesterday from 49ers linebacker Julian Peterson to Eli Manning, especially for the way Manning has matured as a quarterback in one season. “You can tell he knows the game a little bit better now,” Peterson said.

The praise stopped, however, when Peterson said that young Eli can be shaken in the pocket and that the Niners plan to do plenty of shaking in Sunday’s game in San Francisco.

“At times you can get him rattled,” Peterson said. “When the pressure gets to him a little bit, he kind of looks at the pressure first and then decides to throw where he has to throw. If we continue to put on a lot of heat in his face like last week [vs. the Buccaneers], then we’ll be successful at what we have to do.”

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The buzzwords flying around Giants Stadium were “trap” and “letdown.”

“I definitely didn’t use those words,” coach Tom Coughlin said. So what was Coughlin’s message to the Giants, who are 5-2 and a double-figure favorite against the 2-5 49ers?

“I simply zoomed in on their home schedule and how they have played at home,” he said, “and talked about the Tampa Bay team going in there.” The Niners last week beat the Bucs (who were 5-1) 15-10.

RB Tiki Barber was named the NFC Offensive Player of the Week for his career-high 206-yard rushing performance in a 36-0 trouncing of the Redskins. Barber was on his way to breaking the Giants’ singlegame rushing record of 218 yards set by Gene Roberts in 1950 but he took himself out of the game for the entire fourth quarter. “I have to keep some of the records alive,” Barber said, “otherwise I won’t want to play anymore.”

Rookie DE Justin Tuck, wearing a boot on his left foot, will miss at least two weeks with a left medial ankle sprain suffered in the rout of the Redskins. “You never want to have a setback, especially not right now,” said Tuck, who had been rotating in with Osi Umenyiora, a sign of his rapid development.

Special-teams ace David Tyree missed last week’s game with a sprained left elbow and is working this week wearing a protective brace. “I’ve got to trust that it’s not going to conk out on me,” Tyree said of his elbow.” . . . LB Carlos Emmons (torn pectoral muscle) did not practice and appears at least one week away . . . S Shaun Williams (hamstring) also did not practice but is expected to work today . . . CB Will Peterson will be reevaluated today and hopes to be able to resume practicing if he receives good news regarding his back. Peterson has been inactive the past five games with a stress reaction in his lower back.